The known system has two electric motors, which are connected mechanically to one another via a common shaft. A compressor or a compressor system can be arranged as load on the shaft. The rotating components, e.g., the shaft, the rotors of the compressor, clutches between motor shafts and the compressor shaft and also the rotors of the motors, are referred to as the string.
It is known that such systems have natural oscillations. Campbell diagrams are used for the analysis and also for the documentation of such natural oscillations.
One disadvantage with such a system has proven to be that the electric motors can excite natural oscillations of the string. These natural oscillations therefore should be damped or their excitation should be prevented since the natural oscillations could otherwise damage or even destroy the system.